Wake potential expansion using Gaussian basis functions

A method is described to decompose arbitrary bunch distributions into a set of Gaussian basis functions. This expansion allows the reconstruction of the wake fields generated by the bunch in its vacuum chamber environment. It is shown that the triangular-shaped basis function which have been used so far lead to substantial problems in the wake field representation. The accuracies achieved with gaussian and triangular basis functions are compared. The results show that Gaussian basis functions are more suitable to model the wake fields of the beam.